Changes in neutrophil aggregation and chemotaxis response during 18-hour cold storage

Providing neutrophil transfusions to septic neonatal patients with depleted neutrophil reserves can be troublesome and require unscheduled blood donations. Buffy coats from stored whole blood are a potential source of neutrophils provided they remain viable during the interval between the whole blood collection and the buffy coat production. This study determined neutrophil function during storage of whole blood at 4 degrees C for 18 hours. Whole blood pH, hematocrit, platelet, and white cell counts remained unchanged. Chemotactic response to formyl methionyl leucyl penylalanine (FMLP) declined from 172.5 +/- 29 units (mean +/- SD) to 125 +/- 48 at 9 hours and 63.6 +/- 48 (p less than 0.05) at 18 hours. Aggregation response to FMLP remained normal for 9 hours but dropped to 15.5 percent of normal after 18 hours. Neutrophil response to cytaxins was maintained for at least 9 hours during storage of whole blood at 4 degrees C but seriously declined within 18 hours. Limiting 4 degrees C storage of whole blood to 9 hours prior to preparing buffy coats may provide flexibility needed for urgent provision of neutrophil transfusions.